Phase Diagrams Overview

A graphical representation showing the thermodynamic states (solid, liquid, gas) of a substance at different pressures and temperatures.

Lines on a phase diagram that represent the conditions where two different phases of a substance coexist in equilibrium.

A specific point on a phase diagram where three different phases of a substance coexist in equilibrium, at a single temperature and pressure.

The line on a phase diagram that separates the solid and liquid states. Below the solidus line, the substance is stable as a solid.

The line on a phase diagram that separates the liquid and solid states. Above the liquidus line, the substance is stable as a liquid.

A phase diagram that shows the relationship between pressure and temperature for a single substance.

A phase diagram that shows the relationship between pressure, temperature, and specific volume for a single substance.

Phase diagrams that consider the effect of concentration on the phase of a substance.

A homogeneous crystalline structure with one or more atoms or molecules that are substituted for the original atoms or molecules without affecting the structure.

A mixture of two or more metals, often created by melting and mixing the constituent metals.

The proportion of each phase (solid, liquid, gas) present in a system at equilibrium.

A thermodynamic rule that predicts how many degrees of freedom a system has at equilibrium based on the number of phases and components.

The number of independent variables (e.g., temperature, pressure) that can be changed without altering the number of phases in a system at equilibrium.

A system where the equilibrium can only exist at a single set of values for all state variables (e.g., temperature, pressure, composition).

A system where the state of the stable phases depends on the value of just one variable (e.g., temperature).

The composition of two phases (liquid and solid) in a system at equilibrium.

A type of alloy where the constituent elements don't interact chemically in the solid state. The structure is a mixture of separate particles of each element.

A type of alloy where the constituent elements chemically react to form a new compound with unique properties.

A type of alloy where one element dissolves into another, creating a homogenous mixture in the solid state.

The ratio of atoms of different elements in a chemical compound. It's expressed by a simple formula like NaCl (sodium chloride).

A specific arrangement of atoms in a solid material, creating a repeating pattern.

The point at which a solid changes into a liquid. For chemical compounds, it's the point where the compound breaks down into its constituent elements.

A type of bond found in metallic compounds where positive ions are held together by a sea of free electrons.

A process that transforms fine raw materials like iron ore, coke, limestone, etc., into a larger, solid mass (sinter) suitable for use in blast furnaces. This involves burning the materials together on a moving grate, causing them to melt and fuse.

A crucial component in the sintering process, acting as a continuous belt that moves the raw materials through the intense heat. It's where the magic of sintering happens!

The solid, fused product created during the sintering process. It's like a baked brick of iron, ready to be used in a blast furnace.

A large industrial furnace where iron ore, coke, and other materials are melted and chemically transformed into liquid iron. This is the heart of iron production.

The molten iron produced in a blast furnace after the iron ore is reduced and melted. This iron is the primary product of the blast furnace.

A solid solution is a type of homogeneous mixture where one substance is uniformly distributed throughout another in a crystalline structure.

The two or more elements in a solid solution form a single, coherent crystal structure with a uniform distribution of atoms.

Solid solutions have a single type of crystal lattice, just like pure metals.

Solid solutions can exist within a range of concentrations, unlike chemical compounds which have fixed ratios.

Atoms of the solute (the substance that dissolves) are incorporated into the lattice structure of the solvent (the substance that does the dissolving) in solid solutions.

Substitutional solid solutions form when atoms of one element replace atoms of the base metal in the lattice. This is common with elements that have similar atomic sizes.

Interstitial solid solutions form when smaller atoms of solute occupy the spaces between atoms of the base metal.

With unlimited solubility, any amount of one element can be dissolved in another. This is possible when the two elements have the same crystal structure.

A type of alloy where the properties are a blend of the pure components, resulting in a smooth transition between them.

An alloy where the properties don't follow a simple linear relationship and can significantly deviate from the pure components, especially in electrical resistivity.

An alloy with properties that vary linearly within a single-phase solid solution and linearly between phases in a two-phase region, with the extremes representing the pure phases.

A type of alloy where the formation of a chemical compound results in a maximum or minimum point on the property curve, known as the singular point.

A solid carbonaceous material derived from coal, used as fuel in blast furnaces for iron production. It's made by heating coal to high temperatures in the absence of oxygen.

The process of preparing iron for steel production, including steps like melting, refining, and removing impurities.

The production of steel involves multiple interconnected steps, from coke production to finished product preparation, all aimed at transforming raw materials into steel.

The gas produced as a byproduct of coke production, mainly composed of hydrogen, methane, and small amounts of carbon monoxide, carbon, and nitrogen.